The present invention relates to a mounting arrangement for mounting a gas turbine engine on an aircraft, in particular to a mounting arrangement for mounting a turbofan gas turbine engine on an aircraft.
A turbofan gas turbine engine is commonly mounted on an aircraft pylon by a first mounting on the core engine casing and a second mounting on the core engine casing. An example of a first mounting is described in our European patent EP0613444B1 and an example of a second mounting is described in our European patent EP0431800B1. The first mounting transmits thrust loads, side loads and vertical loads to the aircraft pylon. The second mounting transmits torque loads, vertical loads and side loads to the aircraft pylon.
These gas turbine engine mountings are arranged to be statically determinate systems, i.e. six degrees of freedom restraint covering translation in the x, y and z axes with rotational constraint about each axis. The aim in these mountings is to provide one and only one means by which each degree of freedom is restrained, so that component loads may be calculated and xe2x80x9cfightsxe2x80x9d may be avoided. Conventionally, in these mountings each degree of freedom is constrained by a system of ball ended links.
Accordingly the present invention seeks to provide a novel mounting for a gas turbine engine.
Accordingly the present invention provides a mounting arrangement for mounting a gas turbine engine on an aircraft, the gas turbine engine having at least one casing, the mounting arrangement comprises at least one mounting for mounting the at least one casing on the aircraft, the mounting comprises at least one elastic hinge arranged parallel to the axis of the gas turbine engine or at least one elastic hinge arranged in a plane perpendicular to the axis of the gas turbine engine, the at least one elastic hinge is arranged to allow small elastic movements of the mounting within the fatigue limits of the material of the mounting.
The at least one mounting may comprise a first hinge arranged parallel to the axis of the gas turbine engine and a second hinge arranged in a plane perpendicular to the axis of the gas turbine engine.
The at least one mounting may comprise a first hinge arranged parallel to the axis of the gas turbine engine, a second hinge arranged in a plane perpendicular to the axis of the gas turbine engine and a third hinge arranged in a plane perpendicular to the axis of the gas turbine engine.
The at least one mounting may comprise a first hinge arranged in a plane perpendicular to the axis of the gas turbine engine and a second hinge arranged in a plane perpendicular to the axis of the gas turbine engine.
Preferably the gas turbine engine comprises a core engine having a core engine casing, the mounting arrangement comprises a first mounting for mounting the core engine casing on the aircraft and a second mounting for mounting the core engine casing on the aircraft, the first mounting comprises a first hinge and a second hinge, the first hinge is arranged parallel to the axis of the gas turbine engine to form a roll hinge, the second hinge is arranged in a plane perpendicular to the axis of the gas turbine engine to form a pitch hinge, the second mounting comprises a third hinge adjacent the core engine casing and a fourth hinge adjacent the aircraft, the third hinge is arranged in a plane perpendicular to the axis of the gas turbine engine, the fourth hinge is arranged in a plane perpendicular to the axis of the gas turbine engine and the hinges are elastic hinges.
The first mounting may be an upstream mounting and the second mounting is a downstream mounting.
The first mounting may be a downstream mounting and the second mounting is an upstream mounting.
The upstream mounting may be adjacent an upstream bearing housing and the downstream mounting is adjacent a downstream bearing housing.
The first hinge may be adjacent the core engine casing and the second hinge is adjacent the aircraft.
The first mounting may be configured and arranged such that in operation torsion of the first mounting allows the first mounting to act as a vertical hinge.
Preferably the third and fourth hinges are parallel.
Alternatively the gas turbine engine comprises a core engine and a fan, the core engine having a core engine casing, the fan having a fan casing, the mounting arrangement comprises a first mounting for mounting the fan casing on the aircraft, a second mounting for mounting the core engine casing on the aircraft and a third mounting for mounting the core engine casing on the aircraft, the first mounting comprises a first hinge, a second hinge and a third hinge, the first hinge is arranged parallel to the axis of the gas turbine engine to form a roll hinge, the second hinge is arranged in a plane perpendicular to the axis of the gas turbine engine, the third hinge is arranged in a plane perpendicular to the axis of the gas turbine engine, the second mounting comprises a fourth hinge adjacent the core engine casing and a fifth hinge adjacent the aircraft, the fourth hinge is arranged in a plane perpendicular to the axis of the gas turbine engine, the fifth hinge is arranged in a plane perpendicular to the axis of the gas turbine engine, the third mounting comprises at least one thrust strut extending from the core engine casing to the aircraft and the hinges are elastic hinges. Preferably the second and third hinges are parallel. Preferably the fourth and fifth hinges are parallel.
Alternatively the gas turbine engine comprises a core engine and a fan, the core engine having a core engine casing, the fan having a fan casing, fan outlet guide vanes and a nacelle, the fan outlet guide vanes extending radially between the fan casing and the core engine casing, the mounting arrangement comprises a first mounting for mounting the fan casing on the aircraft and a second mounting for mounting the core engine casing on the aircraft, the first mounting comprises the fan casing and the nacelle forming a unified structure, the second mounting comprises a first hinge adjacent the core engine casing and a second hinge adjacent the aircraft, the first hinge is arranged in a plane perpendicular to the axis of the gas turbine engine, the second hinge is arranged in a plane perpendicular to the axis of the gas turbine engine and the hinges are elastic hinges. Preferably the first and second hinges are parallel.
The second mounting may be configured and arranged such that in operation differential side bending of the second mounting allows the second mounting to act as a vertical hinge.
Preferably the gas turbine engine is a turbofan gas turbine engine. Preferably the turbofan gas turbine engine comprises a nacelle arranged substantially coaxially with the core engine.
Preferably an A-frame connects the core engine casing and the nacelle, the A-frame and the second mounting are arranged in a substantially vertical plane containing the engine axis.
Preferably the A-frame is arranged at an angle such that the radially inner end of the A-frame is at a different axial position to the radially outer end of the A-frame.
Preferably the second mounting is arranged at an angle such that the radially inner end of the second mounting is at a different axial position to the radially outer end of the second mounting.
Preferably the aircraft, nacelle, first mounting and second mounting form a unified structure.
Preferably the first mounting and the second mounting are mounted on a pylon of the aircraft.
Preferably the pylon extends from the wing of the aircraft or the fuselage of the aircraft.